So in this case, having "normal" gut bacteria is the best option; having all your gut bacteria wiped out is the worst option; and having at least one gut bacteria is better than nothing. Why? The researchers focus on the possible role of gut bacteria in enhancing the body’s antioxidant response, and they do indeed show that antioxidant activity was reduced in the germ-free mice.

And in humans:

Which brings us back to beet juice, whose key ingredient is nitrate, which is converted by friendly bacteria in the mouth to nitrite, which is then converted to nitric oxide, which is what boosts endurance. In this case, then, it’s your oral microbiome rather than your gut microbiome that matters. There’s already some interesting research from back in 2008 showing that, if you use an antibacterial mouthwash, you completely wipe out the benefits of ingesting nitrate.

Interesting stuff. I’m not going to go out and tell anyone to avoid antibacterial mouthwash but, if you take beet juice for performance benefit, you might want to think about your timing. Further, I’d say we should probably at least be aware of these things. Just don’t go overboard. As mentioned in the end, probiotics aren’t a panacea.

This article presents further evidence that, for many people, swearing (cursing) provides readily available and effective relief from pain. However, overuse of swearing in everyday situations lessens its effectiveness as a short-term intervention to reduce pain.

Used in the right situation, maybe we could tap into this to overcome the pains of racing and run faster. Just be careful. You don’t want to upset parents of young children because you’re flying into the finish line screaming every four letter word in existence. You also don’t want to overdose, as much as you might want to at times.